HMChO 2026 will be held virtually on February 21. Registration is OPEN!
A PDF detailing the information below is also available here.
Note: The following regulations apply for the virtual 2026 competition and may be subject to change as we transition to in-person competitions in future years. Further details will be provided after the conclusion of the 2026 competition.
HMChO follows a format modeled after the U.S. National Chemistry Olympiad (USNCO) in order to ensure a rigorous assessment of students across the multiple areas of chemistry.
There will be no hands-on lab section in the 2026 competition. The exam will be split into two parts as follows:
Part I: 90 minutes for 60 multiple-choice questions;
Part II: 105 minutes for 8 written-response problems (an additional 15 minutes will be allowed for scanning and uploading);
Scoring Formula: Total Score = 1.25 × Part I Score + Part II Score.
The competition is open to all high school students in grades 9 through 12 worldwide. Students from all countries are invited to participate. All participants will compete against each other in the same division.
To ensure accessibility, HMChO 2026 will be conducted entirely online. We ask students to adhere to the following proctoring guidelines to maintain the integrity of the competition (for concerns regarding data privacy, see Section 5 of these regulations).
Participants will be added as a student in the course HMChO 2025 on Gradescope, where they will receive the exam questions and will submit the exam solutions.
To set up the account, participants will receive an email with further instructions after registering for the competition. Note that students must remember the email and password used in order to be able to access their Gradescope account on the day of the competition.
To ensure there are no technical issues, we encourage students to set up their account a few days before the competition and to familiarize themselves with the platform. On Gradescope, there will be a practice test, which will already be open for submissions in order to give the students a chance to see how to submit their work, as well as the exam tests, which will only be open for submissions during the period of the proctored competition. Participants can find their assigned participant ID under the account section of Gradescope, which will be used to check rankings once results are published.
Participants will receive an individual Zoom link (there will be multiple Zoom sessions running at the same time in order to ensure an appropriate number of students per proctor) to join during the competition.
Participants must join their designated Zoom session 15 minutes before the scheduled exam time;
Upon entering the Zoom session, each student will be placed in a one-person breakout room, where a proctor will verify their identity by checking their ID on camera and will also verify their camera setup follows official guidelines (for details, see Note 1 of these regulations).
Once verification is complete, each student will be admitted into a larger breakout room of 10-15 students, where a proctor will continuously monitor the cameras of the students in order to ensure a fair examination environment.
The exam will be split into two parts as follows, with a 30 minute break between them. Part I will consist of 60 multiple-choice questions answered directly on GradeScope in the 90 minute exam period. Part II will consist of 8 written-response problems answered on paper in the 90 minute exam period. Answers can be uploaded onto the platform while still under live proctoring in the 15 minutes after the end of the examination period.
For the exam period, we ask students to adhere to the following rules.
If participants have questions during the competition, they should click the "Raise Hand" button in the Zoom meeting and one of the proctors will reach out directly.
Participants are allowed to leave their rooms for bathroom, food, or other types of breaks during the 30 minute break between parts as long as they are back and ready 5 minutes before the scheduled time of the next period.
Failure to adhere to the following will result in an immediate expulsion unless in the case of technical issue/emergency.
Participants should have their cameras on at all times during the competition.
Participants are not allowed to leave their rooms during the two 90 minute examination periods unless approval has been granted before the competition by the HMChO organizing team for medical reasons (for details, see Note 2 of these regulations).
Participants must remain in their designated Zoom session during the entire exam (including the 30 minute break).
If participants get disconnected from Zoom or Gradescope because of technical issues, they should immediately email the HMChO organizing committee at hmcho.inquiries@gmail.com.
To maintain fairness, only the following materials are allowed during the competition:
White or lined paper
Writing utensils (pen/pencil)
Calculator (non-graphing, non-programmable)
The USNCO Equations Sheet and Periodic Table will be provided on the exam page. Students should NOT have a printed copy in front of them during the exam.
All other materials, including textbooks, external human or AI assistance, paper/electronic notes, or any type of devices, are strictly prohibited. The use of unauthorized materials will result in an immediate disqualification.
HMChO is committed to maintaining the highest standards of academic integrity. By registering for the competition, students affirm their commitment to academic honesty and agree to uphold a fair and professional examination environment.
Any violation of these rules may result in warnings, score deductions, and even disqualification depending on the severity of the violations as follows:
No External Assistance: Participants must complete the exam independently without collaboration with others or use of unauthorized resources. Any clear attempt to use non-allowed materials will result in immediate expulsion.
Strict Compliance with Proctoring Protocols: Participants must follow all proctoring instructions, including identity verification, camera setup requirements, and live monitoring procedures. Any clear attempt to evade security measures will result in immediate expulsion.
Suspicious Behavior: Proctors will issue warnings for any activity that raises concerns about exam integrity, including but not limited to frequently looking down at an unseen surface, hands not being visible on the table or keyboard for extended periods, unusual movements suggesting the presence of unauthorized materials or devices. A first warning will be given with the benefit of the doubt, a second warning will be given with score deduction, and a third warning will be given with expulsion from the competition.
Top-performing participants in HMChO 2026 will receive recognition for their achievements. Official results will be announced after the competition.
Each participant's total score is calculated using the following formula: Total Score = 1.25 × Part I Score + Part II Score.
Part I scoring will be based only on the number of correct answers, with a maximum of 60 questions × 1.25 pts = 75 pts possible on Part I. Part II solutions must be detailed, with all work shown. Each of the 8 questions will be weighed approximately equal, with a total of 100 points on Part II.
In the event of a tie, the following tiebreaker procedure will be applied:
Part I and II Analysis: If there is a significant difference in Part I and II between the papers, then the paper with the higher score in Part II will be ranked higher.
Item Analysis for Part II: If there is not a significant difference in Part I and II between the papers, then an analysis of the problems from Part II is made and the paper with the most correct answers on harder problems will be ranked higher.
Item Analysis for Part I: If there not is a significant difference in Part I and II between the papers and the tie still persists after item analysis for Part II, then an analysis of the problems from Part I is made and the paper with the most correct answers on harder problems will be ranked higher.
If the tie remains unresolved, the HMChO organizing committee reserves the right to adjust the number of awards and/or the tiebreaker policy as necessary.
Solutions will be posted on the website for both Part I and Part II exams. Appeals will not be accepted under normal circumstances. However, if participants believe that there is an error in the answer keys, they may submit a protest to the HMChO organizing committee at hmcho.inquiries@gmail.com in the span of 24 hours from the publishing of the answer keys on the website.
Top-performing participants in the HMChO will receive prestigious recognition for their achievements. Official results will be announced after the competition. Awards will be:
Top 10 students: Presented to the top 10 students;
High Honors: Presented to the top ~5% of students;
Honors: Presented to the top ~15% (next 10%) of students;
HMChO values participant privacy and ensures that all personal data provided is kept confidential. Therefore, the data provided during registration is used strictly for competition-related purposes, including registration, results processing, and award distribution, with only authorized organizers and no other third parties having access to this data. Any updates to this policy will be communicated in advance. If participants have concerns about data usage, storage, or privacy, they can contact the HMChO organizing committee at hmcho.inquiries@gmail.com.
Participants must position their laptop or webcam at an angled side view, ensuring both their workspace (table, hands, and writing surface) and at least some part of their upper body remain visible at all times. See below examples for how the set-up should look like:
For further inquiries or clarifications about these regulations, please contact the HMChO organizing committee at hmcho.inquiries@gmail.com.